Kid in Journey to the Center of the Earth.
In remake in 2008 there was a 13 year old.
I am glad you overlooked that remake which along with
the Time Machine remake tried to ruin two of my favorite childhood memory favorite movies.
Sorry I wasn’t specific and you are right I shouldn’t criticize adaptations as I did.
The casting of Pat Boone (like Frankie Avalon in Voyage to the Bottom of the Sea) was to appeal to teenage fans. Does that make us feel old? Yes.
Alec (played by Pat Boone) was simply the movie version of Axel Lidenbrock (Prof. Lidenbrock's exuberant, naive nephew). So there was no significant change to the character. (Though I don't recall any singing in the novel.)
Regards,